Antimicrobial Activity of Silver-Containing Dressings is Influenced by Dressing Conformability with a Wound Surface

Author(s): 
Samantha Jones, BSc; Philip G. Bowler, MPhil; Mike Walker, PhD

Disclosure: All authors are paid employees of ConvaTec Ltd, Flintshire, United Kingdom.

W ound tissue can provide a favorable environment for microbial colonization with a variety of aerobic and anaerobic bacteria.1 Although wound colonization per se is not an indication of infection, factors, such as diabetes, immunosuppression, or the concomitant administration of certain medications, can influence the bacterial balance,2 which may lead to a wound bioburden greater than the level manageable by the host.3 As a consequence of these conditions, clinical infection and delayed healing may occur.4 As well as increasing pain and discomfort for the patient, a slow healing or infected wound can result in an increased burden on the healthcare provider in terms of cost and time.5
With the growing presence of antibiotic-resistant strains of bacteria, topical antimicrobial agents, such as silver and iodine, have once more come into clinical favor.5–7 Topical silver has broad-spectrum antimicrobial activity that encompasses many antibiotic-resistant wound pathogens.4 Unlike the case with antibiotics, there is little current evidence of emerging microbial resistance to silver.8 Various wound dressings containing silver are now available for the management of critically colonized and locally infected wounds,8 and these dressings differ in structure and physical properties, type and amount of silver contained in the dressing, and the mechanism by which silver is delivered.9
Managing wound infection and reducing the risk of infection are important objectives in wound management. Good clinical practice should include the correct choice of wound dressing to prevent and manage local infections in at-risk wounds.5 Factors to be considered include the ability of the chosen dressing to manage exudate in heavily exuding infected wounds,10 act as an effective antimicrobial barrier,10 and absorb and retain bacteria.10 The appropriateness of the dressing for the size, depth, and location of the wound is also an important factor in dressing selection. Comparatively little is known about how these properties are modified by local factors at the wound interface.
This study examined 2 silver-containing wound dressings, a silver-containing Hydrofiber® (SCH) dressing (AQUACEL® Ag, ConvaTec, Skillman, NJ, USA) and a nanocrystalline silver-containing (NSC) dressing (Acticoat™, Smith & Nephew, London, UK), that are used in the clinical management of wounds at risk of infection. Both have demonstrated highly efficacious antimicrobial activity against wound pathogens in vitro9 including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE).11–13
Structurally, these dressings differ in their underlying construction and in the mechanisms by which ionic silver is made available.

References: 

References

1. Bowler PG, Duerden BI, Armstrong DG. Wound microbiology and associated approaches to wound management. Clin Microbiol Rev. 2001;14(2):244–269.
2. Sibbald RG, Williamson D, Orsted HL, et al. Preparing the wound bed—debridement, bacterial balance, and moisture balance. Ostomy Wound Manage. 2000;46(11):14–35.
3. Bowler PG. Progression toward healing: wound infection and the role of an advanced silver-containing Hydrofiber dressing. Ostomy Wound Manage. 2003;49(Suppl 8A):2–5.
4. Wright JB, Lam K, Burrell RE. Wound management in an era of increasing bacterial antibiotic resistance: a role for topical silver treatment. Am J Infect Control. 1998;26(6):572–577.
5. White RJ, Cooper R, Kingsley A. Wound colonization and infection: the role of topical antimicrobials. Br J Nurs. 2001;10(9):563–578.
6. Ovington LG. The truth about silver. Ostomy Wound Manage. 2004;50(9A Suppl):1S–10S.
7. Campton-Johnston S, Wilson J. Infected wound management: advanced technologies, moisture-retentive dressings, and die-hard methods. Crit Care Nurs Q. 2001;24(2):64–77.
8. Percival SL, Bowler PG, Russell D. Bacterial resistance to silver in wound care. J Hosp Infect. 2005;60(1):1–7.
9. Parsons D, Bowler P, Myles V, Jones S. Silver antimicrobial dressings in wound management: a comparison of antibacterial, physical, and chemical characteristics. WOUNDS. 2005;17(8):222–232.
10. Tachi M, Hirabayashi S, Yonehara Y, Suzuki Y, Bowler P. Comparison of bacteria-retaining ability of absorbent wound dressings. Int Wound J. 2004;1(3):177–181.
11. Bowler PG, Jones SA, Walker M, Parsons D. Microbicidal properties of a silver-containing hydrofiber dressing against a variety of burn wound pathogens. J Burn Care Rehabil. 2004;25(2):192–196.
12. Jones SA, Bowler PG, Walker M, Parsons D. Controlling wound bioburden with a novel silver-containing Hydrofiber dressing. Wound Repair Regen. 2004;12(3):288–294.
13. Gallant-Behm CL, Yin HQ, Liu S, et al. Comparison of in vitro disc diffusion and time kill-kinetic assays for the evaluation of antimicrobial wound dressing efficacy. Wound Repair Regen. 2005;13(4):412–421.
14. AQUACEL Ag [package insert]. Skillman, NJ: ConvaTec; 2002.
15. Bowler PG, Jones SA, Davies BJ, Coyle E. Infection control properties of some wound dressings. J Wound Care. 1999;8(10):499–502.
16. Robinson BJ. The use of a hydrofibre dressing in wound management. J Wound Care. 2000;9(1):32–34.
17. Acticoat [package insert]. Hull, UK: Smith & Nephew; 2002.
18. Demling RH, DeSanti L. The role of silver in wound healing. Part 1: effects of silver on wound management. WOUNDS. 2001;13(1 Suppl A):5–14.
19. Yin HQ, Langford R, Burrell RE. Comparative evaluation of the antimicrobial activity of ACTICOAT antimicrobial barrier dressing. J Burn Care Rehabil. 1999;20(3):195–200.



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